scholarly journals Earthquake Risk of Gas Pipelines in the Conterminous United States and Its Sources of Uncertainty

N. Simon Kwong ◽  
Kishor S. Jaiswal ◽  
Jack W. Baker ◽  
Nicolas Luco ◽  
Kristin A. Ludwig ◽  
2015 ◽  
Vol 172 (8) ◽  
pp. 2265-2276 ◽  
Yongxian Zhang ◽  
M. Burak Yikilmaz ◽  
John B. Rundle ◽  
Xiangchu Yin ◽  
Yue Liu ◽  

Andrew Cosham ◽  
Phil Hopkins

Pipelines are aging: more than half of all pipelines in Europe and the United States are over 40 years old. Historically, only a small number of pipeline failures have been attributed to fatigue; however, as pipelines age, this might change. Indeed, two of the most serious pipelines failures in recent years in the United States were partly attributed to fatigue. The issue with fatigue is not so much how it should be addressed, but if or when, and where, it will become more of a problem. Historical failure data provides a valuable insight into the number and cause of failures that have been attributed to fatigue, and an indication of what might happen in the future. Historical failure data for onshore gas and liquid pipelines in the United States of America and Canada has been reviewed in order to estimate the number and cause of failures that can be attributed to fatigue; specifically, the OPS 30-day Incident Reports, the listing of pipeline rupture events compiled by the National Energy Board, and the findings of failure investigations conducted by the National Transportation Safety Board (NTSB) and the Transportation Safety Board of Canada (TSB). Failures that can (at least partly) be attributed to fatigue are not readily identifiable in the historical data, because fatigue is not listed as a secondary cause (as it is, strictly, only a growth mechanism). The narrative descriptions in historical data sets, as in the OPS 30-day Incident Reports, and the detail in the Pipeline Investigation Reports or Accident Briefs published by the NTSB, and the Pipeline Investigation Reports published by the TSB are essential for identifying the relevant failures and their causes. Failures in pipelines that can be attributed to fatigue are relatively rare, but fatigue failures have been reported in both onshore gas and liquid pipelines in both the United States and Canada, mostly originating from pre-existing mechanical damage or manufacturing defects. Corrosion-fatigue has been identified as a contributing factor in a minority of the failures. The number of failures in liquid pipelines is (as would be expected) higher than that in gas pipelines. The number of failures in onshore liquid pipelines in the United States that can be attributed to fatigue has increased, with over half of such failures having occurred in the last ten years. The increase is statistically significant. There has also been an increase, albeit smaller and not statistically significant, in the number in onshore gas pipelines. The increase in the number of failures is consistent with an ageing system.

2020 ◽  
Vol 91 (3) ◽  
pp. 1763-1775 ◽  
Monica D. Kohler ◽  
Deborah E. Smith ◽  
Jennifer Andrews ◽  
Angela I. Chung ◽  
Renate Hartog ◽  

Abstract The ShakeAlert earthquake early warning system is designed to automatically identify and characterize the initiation and rupture evolution of large earthquakes, estimate the intensity of ground shaking that will result, and deliver alerts to people and systems that may experience shaking, prior to the occurrence of shaking at their location. It is configured to issue alerts to locations within the West Coast of the United States. In 2018, ShakeAlert 2.0 went live in a regional public test in the first phase of a general public rollout. The ShakeAlert system is now providing alerts to more than 60 institutional partners in the three states of the western United States where most of the nation’s earthquake risk is concentrated: California, Oregon, and Washington. The ShakeAlert 2.0 product for public alerting is a message containing a polygon enclosing a region predicted to experience modified Mercalli intensity (MMI) threshold levels that depend on the delivery method. Wireless Emergency Alerts are delivered for M 5+ earthquakes with expected shaking of MMI≥IV. For cell phone apps, the thresholds are M 4.5+ and MMI≥III. A polygon format alert is the easiest description for selective rebroadcasting mechanisms (e.g., cell towers) and is a requirement for some mass notification systems such as the Federal Emergency Management Agency’s Integrated Public Alert and Warning System. ShakeAlert 2.0 was tested using historic waveform data consisting of 60 M 3.5+ and 25 M 5.0+ earthquakes, in addition to other anomalous waveforms such as calibration signals. For the historic event test, the average M 5+ false alert and missed event rates for ShakeAlert 2.0 are 8% and 16%. The M 3.5+ false alert and missed event rates are 10% and 36.7%. Real-time performance metrics are also presented to assess how the system behaves in regions that are well-instrumented, sparsely instrumented, and for offshore earthquakes.

1959 ◽  
Vol 49 (2) ◽  
pp. 123-162
C. F. Richter

abstract In the USSR earthquake risk is now officially mapped by division into areas numbered with the degrees of the Modified Mercalli intensity scale, to show maximum reasonably expectable intensity during future earthquakes on ground of the prevailing character. This paper presents and discusses maps on the same plan for the Los Angeles Basin and its vicinity, for California, and for the United States. The effect of variation of ground from point to point can be shown only on a large scale. This is microregionalization; the map for the Los Angeles Basin is an example. Small-scale regionalization maps require generalization. Prevailing ground is selected, not strictly by percentage of area, but by considering the foundation likely to be used for construction, in mountainous areas mostly small alluvial patches less stable than the surrounding rock. Regionalization and especially microregionalization can be used in construction and planning, as indicating maximum effects to be considered in designing permanent structures. In adjusting insurance rates, and in designing temporary structures, statistical frequency of occurrence is also involved. Over small areas, regionalization depends largely on local variation of ground and geology; over large areas, distance from active faults must be considered. Attention should be given to the effect of structural trends and of wave path on the form of isoseismal curves. Mapping for the Los Angeles Basin area is reasonably definite. That for California is fairly reliable, but less so in desert and mountain areas. That for the United States is in part highly speculative and subject to substantial change.

2008 ◽  
Vol 45 (3) ◽  
pp. 735
Alex Ross

This article provides an overview of the alternative rate making methodologies adopted by the United States Federal Energy Regulatory Commission (FERC) in itsregulation of transportation rates for oil and natural gas pipelines. In 1997, authority over rate making for interstate oil and natural gas pipelines was transferred to the newly created FERC. This article describes the history of interstate pipeline rate making and the transfer of rate making authority to the FERC.The author looks at the innovative pipeline rate making methodologies implemented by the FERC in its regulation of transportation rates for both oil andnatural gas pipelines. The article describes the adoption by FERC of market based rates and a generally applicable indexed rate cap methodology for oil pipelinerate setting. In respect of natural gas pipelines, the legislative requirements and practical realities associated with cost-of-service rate making by FERC aredescribed and FERC’s policies permitting selective discounting, shipper-specific negotiated rates, and market based rates for natural gas pipelines arereviewed.The Commission’s adoption of the alternative rate making methodologies has taken the emphasis off of general rate case litigation as a means of establishingjust and reasonable rates for interstate oil and natural gas pipelines and related facilities. The alternative rate making methodologies also represent a significantdeparture from cost-of-service rate making, with increasing focus on rate flexibility and competition as a means of generating efficiencies for customers of interstate oil and natural gas pipelines.

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